The treatment of chronic rhinosinusitis (CRS) differs from acute rhinosinusitis, where the known bacterial cause can be successfully treated with a variety of drug therapies. However in CRS, the past inability to identify a single causative factor had resulted in a lack of potential targets for therapeutic intervention. To date, the Food and Drug Administration has not approved any medication for the prevention or treatment of CRS.

Existing interventions have largely focused on the use of antibiotics, inhaled or oral corticosteroids, and surgery. Antibiotics are most useful in treating acute exacerbations that result from bacterial invasion of the damaged epithelial tissue that characterizes CRS. However, no antibiotic is effective in preventing the triggers for the tissue-damaging eosinophilic inflammation, and antibiotics are not effective in eradicating the causative factors for CRS.

Oral and inhaled corticosteroids have been used to reduce inflammation and decrease the body's immune response to the fungi by preventing eosinophilic production, migration, activation and life prolongation. However, corticosteroids can cause serious side effects and must be avoided or used in caution in certain patients, such as those with gastrointestinal ulcers, renal disease, hypertension, diabetes, osteoporosis, thyroid disorders, and intestinal disease.

Surgical intervention has been used extensively in patients with chronic rhinosinusitis who are refractory to traditional medical therapy and in patients with recurrent acute rhinosinusitis in which an obstruction to sinus drainage can be identified. Limited surgery in the area of the ostiomeatal complex, that area into which the anterior ethmoid, maxillary, and frontal sinuses drain, is often used to improve the drainage of these sinuses and allow better delivery of topical medications to the sinuses. In addition, endoscopic sinus surgery can effectively remove inflamed tissue and trapped mucus, increase the drainage and ventilation of the sinuses, and improve the symptoms of many sinusitis sufferers. Unfortunately, in many cases this relief is only temporary.

Work completed by researchers at the Mayo Clinic, which first revealed the presence of fungus as a probable cause for CRS, has also led to the availability of a new treatment option. In their work and other studies, topical antifungal medications, such as amphotericin B, have reduced inflammatory mucosal wall thickening and decreased the production of inflammatory mediators such as IL-13 and IL-5 and the resultant eosinophilic migration.(1, 2, 3)

References

1. Ponikau JU, Sherris DA, Kita H, et al. Intranasal antifungal treatment in 51 patients with chronic rhinosinusitis. J Allergy Clin Immunol. 2002;110:862-6.
   
   
2. Ricchetti A, Landis BN, Maffioli A, et al. Effect of anti-fungal nasal lavage with amphotericin B on nasal polyposis. J Laryngol Otol. 2002;116(4):261-3.
   
   
3. Sherris DA, Ponikau JU, Weaver A, et al. Treatment of chronic rhinosinusitis with intranasal amphotericin B: A prospective, randomized, placebo-controlled trial. J Allergy Clin Immunol. 2005;115:125-31.